Spring months create dam safety concerns due to combinations of intense or long lasting rainfall, melting snow, strong wind and the shedding of dead vegetation.
Most dam failures occur from overtopping of the embankment by flood waters or from piping caused by uncontrolled seepage through the embankment or foundation.
Follow these Best Practices
- Conduct inspections following extreme weather events. This is especially important at dams categorized as “high hazard potential”.
- Remember that changes in land use, such as construction, logging and farming can cause runoff into the pool.
- Remove debris stuck in trashracks, culverts, spillways or ditches that can block drainage or reduce discharge capacity.
- Remove loose material from the perimeter of the pool area that can float if the pool level rises.
- Investigate changes in seepage quantity, abnormal or colored seepage, boils, whirlpools or saturated ground which may indicate uncontrolled seepage.
- Investigate embankment cracks, slumping or bulging that can indicate slope failure.
- Repair wave erosion on the upstream slope or erosion gullies on the downstream slope that can weaken the embankment.
- Repair riprap erosion protection in spillways and ditches that is displaced from waves or large flows.